title: Focal-onset myoclonic seizures and secondary bilateral synchrony.
abstract: We present a child with myoclonic seizures, epileptic spasms and generalized epileptiform discharges on scalp EEG. Magnetoencephalography and coherence-phase analysis for scalp EEG suggested focal onset in the left hemisphere. Intracranial video EEG confirmed seizure onset in the left frontal lobe with ictal high-frequency oscillations. Left frontal lobectomy suppressed his seizures. Subsets of myoclonic seizures can be focal in origin despite bilaterally synchronized epileptiform discharges on scalp EEG.
authors.affiliation: Divisions of Neurology and Neurosurgery, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Akiyama
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Donner
authors.forename: Cristina Y
authors.initials: CY
authors.lastname: Go
authors.forename: Ayako
authors.initials: A
authors.lastname: Ochi
authors.forename: O Carter
authors.initials: OC
authors.lastname: Snead
authors.forename: James T
authors.initials: JT
authors.lastname: Rutka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Otsubo
mesh_terms: D000200:Action Potentials; D001931:Brain Mapping; D002675:Child, Preschool; D003344:Cortical Synchronization; D055423:Diet, Ketogenic; D018450:Disease Progression; D004569:Electroencephalography; D004831:Epilepsies, Myoclonic / Q000503:physiopathology*; D017034:Epilepsy, Frontal Lobe / Q000503:physiopathology* / Q000601:surgery; D004830:Epilepsy, Tonic-Clonic / Q000178:diet therapy / Q000503:physiopathology*; D005625:Frontal Lobe / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D019635:Neurosurgical Procedures; D014741:Video Recording